title: Water exchange-minimizing DCE-MRI protocol to detect changes in tumor vascular parameters: effect of bevacizumab/paclitaxel combination therapy.
abstract: OBJECTIVE
  The purpose of this study was to assess changes in the tumor microvasculature induced by combination antiangiogenic therapy in MCF-7 breast tumor mouse models, using a noninvasive DCE-MRI method that minimizes the effect of water exchange.
  
  
  METHODS
  3D quantitative DCE-MRI images were acquired with a heavily T1-weighted saturation recovery gradient echo sequence with a recovery delay of 20 ms. Tumor vascular volume (VV) and vascular permeability-surface area product (PS) were obtained through a linear regression of the albumin-Gd-DTPA-enhanced dynamic image intensity on MCF-7 breast tumor mouse models treated with combination bevacizumab/paclitaxel therapy.
  
  
  RESULTS
  Measured tumor VV values were significantly higher than the values that have been reported previously using quantitative T1 mapping, and are in good agreement with micro-CT (computed tomography) results reported earlier from other tumor models. A trend of decreasing tumor PS was detected in the group of MCF-7 tumor bearing mice treated with the bevacizumab/paclitaxel combination regimen.
  
  
  CONCLUSIONS
  VV and PS maps obtained by a heavily T1-weighted acquisition protocol revealed the large peripheral blood vessels as well as the permeable areas within the tumor. A 12-day/three-dose combination treatment of bevacizumab and paclitaxel resulted in delayed tumor growth and a trend of decreasing tumor vascular permeability surface area product.
authors.affiliation: Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA, zhu@mri.jhu.edu.
authors.forename: Wenlian
authors.initials: W
authors.lastname: Zhu
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kato
authors.forename: Dmitri
authors.initials: D
authors.lastname: Artemov
mesh_terms: D000465:Algorithms; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D016477:Artifacts; D000068258:Bevacizumab; D001834:Body Water / Q000378:metabolism; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D061986:MCF-7 Cells; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D016513:Mice, SCID; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D017239:Paclitaxel / Q000008:administration & dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068258:Bevacizumab; D017239:Paclitaxel